1. Field of the Invention
The present invention relates to a method for manufacturing a head gimbal assembly, a method for manufacturing a hard disk drive, a head gimbal assembly, and a hard disk drive.
2. Related Background Art
In order to increase the density and the capacity of a hard disk drive, the need for thin film piezoelectric actuators for use in high precision positioning mechanisms for tracking is becoming increasingly high in recent years. By arranging a thin film piezoelectric actuator in a head gimbal assembly comprised of a head slider and a suspension to which the head slider is mounted, the head slider can be minutely displaced using a thin film piezoelectric actuator. Thus, it is possible to obtain a head gimbal assembly capable of controlling the position of a head slider with high precision. Japanese Patent Application Laid-Open No. 2004-281651 describes an example of such a thin film piezoelectric actuator.
The thin film piezoelectric actuator described in Japanese Patent Application Laid-Open No. 2004-281651 includes a pair of piezoelectric device units 1, 2 arranged on the surface of a substrate in mirror symmetrical form. The piezoelectric device unit 1 includes two laminated thin film piezoelectric devices 4, 5, that is, two piezoelectric layers. The piezoelectric device unit 2 also has the same configuration. By arranging a thin film piezoelectric actuator having one pair of such piezoelectric device units (piezoelectric laminates) in a head gimbal assembly, it is possible to displace the head slider greatly by, for example, expanding and contracting a pair of piezoelectric device units, each of which are in opposite phase with each other.